Metal bending method and machine therefor

ABSTRACT

A METHOD OF BENDING METAL WHICH CONSISTS IN APPLYING PRESSURE TO THE AREA WHERE BENDING IS TO BE EFFECTED, THE FORCE OF THE PRESSURE HAVING A VALUE WHICH APPROXIMATES THAT AT WHICH THE BENDING OCCURS, THE METHOD ALSO INCLUDING AUGEMENTING SUCH PRESSURE, PREFERABLY MANUAL, TO EFFECT THE ULTIMATE DEGREE OF BENDING OF THE METAL, SUCH METHOD BEING PERFORMED BY A MACHINE INCLUDING A DEVICE FOR APPLYING PRESSURE, PREFERABLY A HYDRAULIC DEVICE, AND ANOTHER DEVICE, PREFERABLY MANUALLY POWERED, FOR AURGMENTING THE FORCE OF THE FIRST MENTIONED DEVICE, BUT AT A LESSER PRESSURE VALUE.

Nov. 16, 1971 N, T, HENKEL ETAL 3,620,066

METAL BENDING METHOD AND yMACHINE `TI'lEREFOR Filed June 25, 1969 2Sheets-Sheet 1 f lNvr-NTORS NE v/LLE T. `#ENKEL HARRY wR/GHT B HERMA/vw. scHARER Nov. 16, 1971 N. T. HENKEL ET Al. 3,620,066

METAL BENDING METHOD AND MACHINE THEREFOR 2 Sheets-Shoot Filed June 25,1969 WSU.

L R S E M Y R K E mmmm N .NHGx R ,.r 0 VTRW NEW v 7 N RM MR a NH#h Y mUnited States Patent Oy "ice U.S. Cl. 72-362 6 Claims ABSTRACT OF THEDISCLOSURE A method of bending metal which consists in applying pressureto the area where bending is to be effected, the force of the pressurehaving a value which approximates that at which the bending occurs, themethod also including augmenting such pressure, preferably manual, toeffect the ultimate degree of bending of the metal, such method beingperformed by a machine including a device for lapplying pressure,preferably a hydraulic device, and another device, preferably manuallypowered, for augmenting the force of the first mentioned device, but ata lesser pressure value.

BACKGROUND OF THE INVENTION (l) Field of the invention The inventionrelates to the method of metal bending and machinery therefor.

(2) Description of the prior art To applicants knowledge, metal bendingheretofore has been either by manual manipulation or by metal shapingmachinery. Bending of metal to accuracy desired, particularly heavygauge metal, cannot be effected manually and machinery for bending heavygauge metal to accuracy has never been perfected. Such machinery has thecharacteristics of either bending the metal beyond that desired or failsto bend the metal to that desired. By applicants method and machine,relatively high pressure is employed at the area where the bending is tobe effected, the high pressure having a value which approximates that atwhich bending can occur, and this pressure is augmented by a pressure ofrelatively lesser value, but being sufficient by augmentation to effectthe desired bending.

SUMMARY OF THE INVENTION i The method is carried out by machineryincluding a force, preferably by a hydraulic pressure device, whichforce is applied to the area at which bending is to be effected. Thepressure employed has a value approximating that pressure which isnecessary to effect bending, whereby a slight augmenting of thatpressure will effect bending. The machinery also includes a secondpressure device, which is preferably effected by manual force. Thesecond pressure device is applicable to augment that of the powereddevice to effect the desired bending.

Other features and the advantages of the present invention will beapparent from the following description, reference being had to theaccompanying drawings wherein a preferred embodiment of the invention isill-ustrated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of themachinery for perfecting the bend, together Iwith the hydraulic powerplant for operating the power actuated pressure device, the view alsoshowing in phantom a piece of metal to be bent;

FIG. 2 is a view looking in the direction of arrows 2 of FIG. 1;

Patented Nov. 16, 1971 FIG 3 is a fragmentary view, partly in section,the section being taken along line 3 3 of FIG. 1, but on a larger scale;

FIG. 4 is a fragmentary view, partly in section, the section being takenalong line 4-4 of FIG. 3;

FIG. 5 is a fragmentary View, partly in section, the section being takenalong line 5 5 of FIG. 3;

FIG. 6 is a fragmentary view looking in the direction of arrows 6 ofFIG. 4;

FIG. 7 is a fragmentary sectional view taken along lines 7 7 of FIG. 4;

FIG. 8 is a fragmentary View, partly in section, the section being takenalong the lines 8 8 of FIG. l, but on a larger scale; and

FIG. 9 is a top plan view looking in the direction of arrows 9 of FIG.8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring generally to thedrawings, the metal bending machine is shown at 20; the metal to be bentis shown in phantom at 22 and is in the form of a ring; and the powergenerating machine is shown at 24. The machine 24 is of the standardtype including a truck 26 which houses a pressure generating device suchas a hydraulic pump (not shown) which is driven by an electric motor 28,which is connected to a source of electric current through a controllerdisposed on truck 26.

The truck 26 also houses a reservoir (not shown) from which the pumpdraws the hydraulic fluid. The high pressure outlet of the pump isconnected to a manually controlled valve 32 (FIGS. l and 2), which iscarried by a table 34, by high pressure tube 35 and return tube 36.Suitable valve mechanism 37 is disposed in the high pressure side of thesystem and is manually adjustable to maintain the desired maximumpressure of fluid. Tubes 38 and 39 connect the valve 32 with a hydraulicmotor 40.

The hydraulic motor 40 actuates a shoe 42 which extends upwardly througha slot 44 in the thick steel table top 46. The top of the table carriessteel posts 48 and 50 which receive cylinders 52 and 54. The posts areremovably carried in holes 56 in the metal table top. The holes selectedfor the posts depend upon the shape of the metal to be bent. The metal22 to be bent is disposed between the shoe 42 and the cylinder. Themanually controlled valve 32, -having a manipulating handle 58, iscarried by the table for controlling the flow of fluid from the pump tothe motor.

The force applied by the shoe 42 on the metal 22 is preset bymanipulating the valve mechanism 37 to the maximum force desired. Suchpressure is preset at a value whereby the shoe force on the metalapproximates that force at which bending of the metal can occur. Under acertain condition, the force exerted by the shoe on the metal may placethe metal under slight stress. Still under another condition, the degreeof force exerted by the shoe on the metal is between the twoaforementioned forces. Under .any of the above conditions, auxiliaryforce must be applied onto the metal in order to effect the desiredaccurate bending thereof.

`The auxiliary force may be by any desired extraneous force and isherein disclosed, for illustrating the invention, as a manually appliedforce. The shoe 42 is formed integrally with a reciprocating plate 60which carries a rack 62, the teeth of which receive the teeth of aratchet 64 (FIG. 6). The ratchet is carried by a pin -66 which isslidably carried in a slot 68 on a plate 70, which latter is fixed tothe underside of the table 34. A handle 72 is formed integrally with theratchet 64 for manipulating the rack 62 carried 4by the plate 60.

In operating the mechanism to carry out the method,

the valve 32 is opened to supply fluid to the hydraulic motor 40 whichin turn moves the plate 60 and shoe 42 toward the metal 22, which metalat that time abuts the cylinder 52 on the posts 48 and S0. The shoe 42,upon engaging the metal 22, applies the predetermined, pre-selectedforce onto the metal. After that major force is applied and while it isbeing applied, the auxiliary, relatively less force is applied, whichauxiliary force, when added to the major force, is sufficient to bendthe metal to the desired accurate shape. The auxiliary force, forillustrative purpose only, is applied manually through the ratchet 64and rack 62.

It is emphasized that the manual force being applied through the ratchet64 and rack 62 is by pulling on the handle 72 of the ratchet. It hasbeen found in actual practice that the muscular reaction in pulling ishighly sensitive for imparting the desired manual force to thc shoe, andis far more sensitive than pushing force on the handle.

Referring more in detail to the drawings, the table 34 includes angleiron legs 74 which are braced by a horizontal angle iron frame 76 and anangle iron brace 78. An angle iron 79 is welded to two of the legs 74and supports the manually actuated valve 32. A rectangularly shapedsupport 80 bridges and is welded to two of the sections of frame 76. Anupright pivot support 82 is Welded to the support 80 for a pivot pin 84.

The cylinder 86 of the hydraulic motor 40 is carried by a frame 88having two downwardly extending arms 90, the lower ends of whichstraddle the pivot support 82 and are journaled on the pivot pin 84. Theupper end of the hydraulic ram is in the form of an arm 92 and this armcarries a pivot pin 94. The pin 94 is connected to two pairs of links 96and 98, one pair being disposed on one side of the arm 92 and the otherpair on the opposite side of the arm. Links 96 are pivotally connectedto a pin 100 which is supported by a downwardly extending support 102which is fixed to the underside of the table top 46 by screws 104. Thelinks 98 are pivotally connected by a pin 106 to the opposite side ofthe shoe plate 60.

As seen more clearly in FIG. 4, the plate 60 is provided withlongitudinally, i.e. horizontally extending grooves 108 on oppositesides thereof, and these grooves receive guide rods 110. The guide rodsare fixed to the underside of table top 46 by oppositely disposed rodsupports 112 which are L-shaped in cross-section and fastened to theunderside of the table by screws 113.

Thus it is apparent that as the ram arm 92 is moved upwardly uponopening the valve 32, the supporting frame 88 for the hydraulic cylinder86 will be moved clockwise, as viewed in FIG. 3, forcing the links 98,the pin 106, the shoe plate l60 and the shoe 42 to the right. In thismanner the desired pre-selected and predetermined degree of force isapplied to the shoe 42.

The extent of oscillatory movement that can be imparted to the ratchet64 is governed by angular disposed strips 114. These strips togetherwith the plate 70, are fixed to the underside of the table top by screws116. A strip 118 (see FIG. 6) for slida-bly supporting the handle 72 forratchet 64 is fastened to the underside of the table top 46 by screws120. The handle 72, carrying the ratchet y64, and the pin 66 are pulledto the right, as viewed in FIG. 6, prior to the application of the majorforce whereby the ratchet is disconnected from the rack. Aftercompletion of the application and maintaining of the major force on theshoe, the handle 72 is moved to the left to reengage the ratchet andrack teeth. Thereafter, the operator pulls the handle in a clockwisesdirection to augment the major force.

The degree of augmenting force `being applied can be determined by agauge 122 (see FIGS. 8 and 9). The gauge is suitably fixed to the topside of table top 46 by a plate 124. The gauge is responsive to fluidpressure in an attached cylinder 126, the pressure therein being variedby a piston, the outer rod of which is shown at 128. The exposed end ofthe piston rod is attached to an arm which is fixed by screws 132 toshoe plate 60.

In practicing the present invention, the operator will employ a gauge tothe metal to determine where pressure should be employed. For example,in the embodiment illustrated wherein the metal 22 is a ring or a partof a ring, the gauge would have an arcuate surface, and if the area ofthe metal does not conform to the shape of the arcuate surface of thegauge, i.e. that area must be forced radially inwardly, he will placethat area `between the cylinders 52 and 54 on the posts 48 and 50. Thenthe major force is applied to that area by the shoe 42. The metal willbe confined between the shoe and the abutments provided by thecylinders. As previously explained, the force applied by the shoeapproximate that force at which bending can take place.

The skilled operator, having previously evaluated mentally the degree ofauxiliary force that is necessary to bend the metal to the desiredshape, will pull the handle 72 clockwise, as viewed in FIGS. 1 and 6,and quite often bend the metal to the desired shape by merely onephysical act. Usually, when extreme precision is necessary, severalpullings are effected, each pulling gradually increasing the degree ofbending. These repeated bendings by physical force by the skilledoperator can be effected although hysteresis is taking place in themetal. Thus the accuracy can be attained in a speedy manner.

In certain cases, the gauge is quite helpful. The skilled operator willknow what degree of movement of the gauge hand or hands is necessary toapproach the ultimate degree of augmenting force desired. He will thenapply that desirable augmenting force by observing the extent ofmovement of the hands of the gauge.

It will be understood that if bending of the ring 22 from the insidesurface thereof is necessary, it will be turned so that the shoe 42engages the inside surface and the outer periphery will abut thecylinders 52 and 54. Various size cylinders, such as those shown in FIG.1 at 136 and 138, can be substituted for cylinders 52 and 54. Byselecting the desired holes 56 for the posts 48 and 50 and the desiredcylinders to be put on the post, any desired abutting relationship canbe established between the shoe 42 and the cylinders.

Having described our invention, we claim:

1. The steps in the method of bending metal, which steps include:

(A) applying pressure to the metal at the area where bending is to beeffected;

(B) limiting and maintaining the application of such pressure at a valueshort of the pressure necessary to bend the metal to the ultimate shapedesired;

(C) thereafter bending the metal to the ultimate shape desired byapplying an augmenting pressure to the same area at a lesser value thanthe first mentioned pressure.

2. The steps in the method of bending metal, as defined in claim 1,characterized in that the pressure being applied by the first mentionedstep approximates that pressure at which bending or the metal to be bentcan occur'.

3. The steps in the method as dened in claim 1, characterized in thatthe augmenting pressure is by manual pulling force.

4. The steps in the method as defined in claim 2, characterized in thatthe augmenting pressure is lby manual pulling force.

5. The steps in the method of bending metal as defined in claim 1,characterized in that the metal is of the type which partly reboundsafter being bent, and further characterized in that the application ofthe augmenting pressure effects bending of the metal to that degreebeyond the desired bent shape which, due to the reboundingcharacteristic of the metal, will rebound to the ultimate desired.shape.

5 6 6. The steps in the method as dened in claim 5, char- 3,184,951 5/1965 Hilton 72-389 X acterized in that the augmenting pressure is bymanual 1,906,854 5/ 1933 Heinrich Y72--389 11' f pu mg om CHARLES W.LANHAM, Primary Examiner 5 M. I. KEENAN, Assistant Examiner ReferencesCited UNITED STATES PATENTS 3,333,445 8/1967 Mergler 72-702 X U.S, C1.X.R. 3,209,577 10/1965 Teplow 72-389 72-389, 432, 702

